#include <stdio.h>
#include <conio.h>
int main()
{
   int i,j,demuoc=0;
   printf("Nhap so can kiem tra (so nguyen): ");
   scanf("%d",&i);
   for(j=1;j<=i;j++)
   	{
      	if(i%j==0) 
         	demuoc++;
      }
   if(demuoc==2)
   	printf("\n%d la so nguyen to",i);
   else
   	printf("\n%d khong phai la so nguyen to",i);
   getch();
}
